This invention relates in general semiconductor processing, and more specifically to an improved microelectromechanical switch.
Recently, microelectromechanical switches have attracted much interest as devices that provide an important way of switching radio frequency signals due to their low insertion loss, good isolation, and high power handling. Additionally, microelectromechanical switches allow for very low power requirements compared to other radio frequency switching devices such as p-i-n diodes. However, present microelectromechanical switches experience difficulty providing sufficient radio frequency signal differentiation between the operation of the switch in an on mode versus an off mode. More specifically, impedance across such a microelectromechanical switch when the switch is turned on may not be sufficiently different from the impedance when the switch is turned off. Such an insufficient differential may result in a radio frequency signal being detected across a switch when the switch is in the off position that is not sufficiently different in strength from a radio frequency signal detected across the switch when the switch is in the on position. Such problems in signal differentiation impact the performance of microelectromechanical switches in wireless applications such as, for example, cellular telephony.
In accordance with the present invention, an improved microelectromechanical switch is provided that substantially eliminates or reduces disadvantages and problems associated with previous developed systems and methods.
In one embodiment of the present invention, a microelectromechanical switch is disclosed that includes a substrate, an insulator layer disposed outwardly from the substrate, and an electrode disposed outwardly from the insulator layer. The switch also includes a dielectric layer disposed outwardly from the insulator layer and the electrode, the dielectric layer having a dielectric constant of greater than or equal to twenty. The switch also includes a membrane layer disposed outwardly from the dielectric layer, the membrane layer overlying a support layer, the support layer operable to space the membrane layer outwardly from the dielectric layer.
In another embodiment of the present invention, a method of forming a microelectromechanical switch is disclosed that includes forming a substrate, forming an insulator layer outwardly from the substrate, and forming an electrode outwardly from the insulator layer. The method also includes forming a dielectric layer outwardly from the electrode, the dielectric layer having a dielectric constant of greater than or equal to twenty. The method further includes forming a membrane layer outwardly and spaced apart from the dielectric layer, the membrane layer being spaced apart from the dielectric layer by a support layer.
Various embodiments of the present invention present several technical advantages. One advantage of various embodiments of the present invention is an improved microelectromechanical switch that overcomes disadvantages of previous methods and devices. A further advantage of various embodiments of the present invention is that a microelectromechanical switch is presented that allows for significant signal differentiation between a radio frequency signal detected during the on and off operating modes of a microelectromechanical switch. Another advantage of various embodiments of the present invention is that a microelectromechanical switch is presented that allows for effective switching of radio frequency signals in size critical wireless applications. A further advantage of the various embodiments of the present invention is that a microelectromechanical switch is presented that achieves switching of radio frequency signals without significant power dissipation.
Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims.